Cherry-red embers in a fireplace are at 835°C and have an exposed area of 0.240 m2 and an emissivity of 0.980. The surrounding room has a temperature of 15.0°C. If 50% of the radiant energy enters the room, what is the net rate of radiant heat transfer in kilowatts?
Radiation makes it impossible to stand close to a hot lava flow. Calculate the rate of heat transfer by radiation in kilowatts from 1.00 m2 of 1140°C fresh lava into 35.0°C surroundings, assuming lava's emissivity is 1.
rate of heat tranfer H = Q/t = A e Sigma T^4
here A is area
e is emissivity
Sgma is Stefans constant
T is absolute temperature
H = Q/t = 0.24 * 0.98 * 5.67 *10^-8 *(835 + 273)^4
rate of heat transfer = 20 kWatts
50% of this = 10 k Watts
--------------------------------------
again
H = 1 * 1 * 5.67 *10^-8 * ((1140+273)^4 - (35+273)^4)
H = 225.5 kWatts
Cherry-red embers in a fireplace are at 835°C and have an exposed area of 0.240 m2...
Cherry-red embers in a fireplace are at 875∘C and have an exposed area of 0.2 m2 and an emissivity of 1.0. The surrounding room has a temperature of 21∘C. If 50% of the radiant energy enters the room, what is the net rate of radiant heat transfer, into the room, in kilowatts?
Cherry-red embers in a fireplace are at 875∘C and have an exposed area of 0.2 m2 and an emissivity of 1.0. The surrounding room has a temperature of 21∘C. If 50% of the radiant energy enters the room, what is the net rate of radiant heat transfer, into the room, in kilowatts?
Radiant heat makes it impossible to stand close to a hot lava flow. Calculate the rate of heat loss by radiation from 1.00 m2 of 1140°C fresh lava into 28.2°C surroundings, assuming lava's emissivity is 1 X How is the rate of heat transfer related to the emissivity of the object? What units should you use for the temperatures? kW
Radiant heat makes it impossible to stand close to a hot lava flow. Calculate the rate of heat loss by radiation from 1.00 m2 of 1110°C fresh lava into 36.2°C surroundings, assuming lava's emissivity is 1.
A wall panel is insulated on the back and exposed to solar radiation on the front surface. The exposed surface of the plate has an absorptivity α = 0.8 for radiation (i.e. 80% of radiant energy is absorbed). Solar radiation arrives to the panel at a rate of 1 kW⁄m2. The panel emissivity ϵ = 1 and the surrounding air temperature is 25°C. a. If we assume radiation is the only mechanism of heat transfer, in this scenario determine the...
please solve these questions (a) Calculate the rate of heat transfer by radiation from a car radiator at 120 °C into a 55 °C environment, if the radiator has an emissivity of 0.75 and a 1.1-m surface area. Enter your answer in kilowatts. (b) Calculate the fraction of this radiative power to the total heat transfer by an automobile engine. Assume a mechanical horsepower of 200 hp (150 kW) and the efficienty of automobile engines as 25 %. Express your...